• Proceedings of the KSME Conference
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• 2001.06b
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• pp.70-75
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• 2001

In this study, we developed a measuring system utilizing machine vision for measuring the precision of positioning of micro stepping motor. The measuring system equipped with CCD Camera, ring illumination and diffuser measures the repeatability and the hysterisis of a micro stepping motor by means of the pointer attached to the motor directly. With the measuring system, it was possible to measure the precision of the micro stepping motor in the resolution of $50{\mu}m$.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.26-31
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• 1995

A new actuating mechanism suitable for a micro positioning device is developed using piezo-electric elements. The actuator can make a step movement of 0.5 .mu. m up to 3.5 .mu. m. The step size can be adjusted on demand. By repeating this step action, long distance movement is achieved. Precise positioning can be obtained by combining the coarse motion with the maximum step size and fine motion. Two types of fine motion have been proposed for a driving method. Firstly, feedback control bases on PID is applied. The experimental results for the two method are presented.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.43-51
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• 2010

Speed, accuracy and smoothness are the important properties of pan-tilt camera. In the case of a high ratio zoom lens system, low vibration characteristic is a crucial point in driving pan-tilt mechanism. In this paper, a novel micro-stepping controller with a function of reducing vibration was designed using field programmable gate arrays (FPGA) technology for high zoom ratio pan-tilt camera. The proposed variable reference current (VRC) control scheme reduces vibration decently and optimizing coil current in order to prevent the step motor from occurring missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378kpps micro-step driving, and increase maximum acceleration in motion profiles.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.135-138
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• 2001

This paper presents micro step driving method using VHDL(Very high speed integrated circuit Hardware Description Language) which can configure CPLD(Complex Programmable Logic Device). Using VHDL which can do abstractive programming is similar to high level language. The whole block divided into five parts with freq. divide part, saw-tooth wave generation part, sine-cosine wave generation part, comparative part, out part. In the result of this study, peripheral circuits are to be simple and using LPM(Library of Parameterized Modules) is more easily to configure circuit. It is easy to verify and implement by using VHDL. To subdivide one natural step, we confirm that using micro step driver is expected that the rotor motion is stepless very smooth.

• Transactions of Materials Processing
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• v.11 no.7
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• pp.581-588
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• 2002

Among the processes to produce micro lens, the process using press molding is a new technology to simplify the process, but it contains many unknown variables. The press-molding process proposed in this paper was simplified into two step process, the first step is the pressing to design the preform for glass element, the second step is the annealing to reduce the residual stress. It is important to estimate the amount of shrinkage of glass gob and the residual stress during process. It Is difficult to evaluate the process variables as mentioned above through the experiment. The influences due to process variables was evaluated by using FEM parametric analysis. The results in this paper can be applicable to produce micro lens.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.4
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• pp.62-68
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• 1994

Recently, the trends toward reduction in size and weight of industrial products increased the application of micro hole for manufacturing gadgets of high precision and gave rise to a great deal of interest for micro hole drilling M/C. Quite a few research work is performed on micro drilling on domestic basis compared with the tendency of analyzing cutting mechanism, adaptive control, monitoring of generally available drills of diameter greater than 1mm. This study adresses the design, manufacturing and controlling a micro hole drilling M/C with the overload detection instrument and the step feed mechanism. Controlling and monitoring of the drilling process are acomplished on PC basis for more user interfaces and effectiveness. The test machine of the results of this research shows a good foundation for extending further micro hole machining technique.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.40-45
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• 2010

The flow rate is higher in ACEO micro-pumps with step electrodes than in micro-pumps with planar asymmetric electrodes. In the present study, numerical simulations were made of a ACEO micro-pump with step electrodes to investigate the effects of electrode design parameters on the pumping flow rate. The electrical charge at the electrodes, the fluid flow, and potential were solved, taking into account the finite size of ions, that is, the steric effect. This effect is recognized to be capable of quantifying the electrical charge more accurately in the electrical double layer subject to high voltages. Geometrical parameters such as heights, widths, and gaps of three-dimensional electrodes were optimized to enhance the pumping flow rate. Moreover, the effect of amplitude and frequency of AC was studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.283-284
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• 2007

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.2
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• pp.157-163
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• 2014

This paper proposes a two-stage step-down buck and a tapped-inductor boost cascaded converter for high efficiency photovoltaic micro-inverter applications. The proposed inverter is a new structure to inject a rectified sinusoidal current into a low-frequency switching inverter for single-phase grid with unity power factor. To build a rectified-waveform of the output current. the converter employs both of a high efficiency step-up and a step-down converter in cascade. In step-down mode, tapped inductor(TI) boost converter stops and the buck converter operates alone. In boost mode, the TI converter operates with the halt of buck operation. The converter provides a rectified current to low frequency inverter, then the inverter converts the current into a unity power-factor sinusoidal waveform. By applying a TI, the converter can decrease the turn-on ratios of the main switch in TI boost converter even with an extreme step-up operation. The performance validation of the proposed design is confirmed by an experimental results of a 120W hardware prototype.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.340-344
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• 2004

This paper is the performance evaluation of reverse engineering system using simple mechanism. The existing equipment didn't use in the field popularly as it is too expensive. So we constructed the reverse engineering system of simple mechanism using the laser sensor, LM guide, micro step driver and control program. And we caught the Characteristics to measure some product. Finally we confirmed the precision to compare measured data and CAD date.